During one of the first heavy snows of the winter, on the Interstate outside the Twin Cities, Rushmore McKenzie is behind a truck behaving erratically when the man in the truck bed dumps a body out onto the road, right in front of McKenzie's car. McKenzie avoids hitting the body, a bound woman who is just barely alive, but his stopped car in the middle of the road starts a chain of accidents, resulting in a thirty-seven car pile-up. By the time the police arrive, and the EMTs and ambulances have taken care of the immediate injuries, the truck is long gone.

The injured woman awakens with no memories—not of the accident, not of anything—and is labeled by the police as Unidentified Woman #15. With few leads, the detective in charge, McKenzie's former partner and old friend Bobby Dunston, turns to McKenzie for a favor. Now McKenzie has to try to identify the grievously injured woman and find out who tied her up and dumped her on the freeway to die. And why.